A Chinese netizen in the eastern province of Anhui was detained for more than 100 days on suspicion of involvement in recent calls for a Middle East-inspired "Jasmine" revolution and was tortured, fellow activists said this week.

Wu Lebao was released from criminal detention this week after signing an undertaking not to meet with other activists, according to rights activist Li Wenge.

Li said Wu had lost around 40 pounds and suffered muscle wastage and psychological damage during his time inside.

"When he was in the detention center ... he developed sores because he was only able to sit in a single position and his clothing wasn't changed," Li said. "He wasn't able to move around so he developed circulation problems."

"Physically, he is recovering all right but he still needs to vent emotionally," Li said.

Wuhan-based rights activist Qin Yongmin, who was himself detained by police on Wednesday, said a large number of activists had "disappeared" nationwide in the crackdown on calls for "Jasmine" protests on the streets of Chinese cities.

The protests themselves appeared to attract more police and journalists than participants.

Police would take people to an undisclosed location with black bags over their heads and hold them, sometimes questioning or torturing them, said Qin, who runs a rights newsletter called the China Human Rights Observer.

"One of their most common practices is to have you sitting in one place and not to allow you to move around," Qin said. "Even this is pretty unbearable."

"If you move, they beat you ... They also use various methods of terrorizing people which I won't go into here, because the people themselves don't want to talk about it any more."

Wu was detained on July 13 at the height of a police security clampdown ahead of the ruling Communist Party's 90th anniversary.

He was released on Oct. 28, Li said.

Qin said that in the central province of Hubei, activist Gao Chunlian was detained simply for retweeting a microblog post about the "Jasmine" rallies and adding the word "Guiyang."

Gao was detained in February on suspicion of "incitement to subvert state power," and had yet to be released, he said.

Pressured over boycott

Meanwhile, in the southern city of Guangzhou, rights activist Lin Xuqiang said he had come under intense pressure from state security police after he tried to organize a boycott of China's train services on Sunday in protest at the Wenzhou high-speed rail crash of July 23.

"I have just got a call from the state security police, who are very worked up about this," Lin said.

"If I want to do something for the people of China, I will have to take the pressure," he said. "After all, a lot of people died in the 1911 revolution."

"But I am already middle-aged and single, so I have nothing to lose really," he said.

Lin's campaign was aimed at giving a focus to popular anger over the high-speed rail crash, which drew widespread criticism over official handling of the rescue effort and crash inquiry.

Chinese lawyers, rights activists, and legal experts are mounting an online campaign against proposals to legalize secret detention currently being debated by the country's lawmakers.

China's parliamentary body, the National People's Congress (NPC), is currently debating amendments to the criminal law which could remove a current requirement to inform a person's relatives of their detention.

Chinese authorities have launched an unprecedented crackdown on dissent around the country following online, anonymous calls early this year for a "Jasmine" revolution inspired by uprisings in the Middle East.

International rights groups say that "disappearances" render detainees more vulnerable to abuses like torture.

Reported by Hai Nan for RFA's Cantonese service. Translated and written in English by Luisetta Mudie.